scholarly journals Investigation of adsorption/desorption performance by aminopropyltriethoxysilane grafted onto different mesoporous silica for post-combustion CO2 capture

Clean Energy ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 120-131 ◽  
Author(s):  
Pailin Muchan ◽  
Chintana Saiwan ◽  
Manit Nithitanakul

Abstract Mesoporous silicas with hexagonal structure (MCM-41 and SBA-15) and cubical interconnected pore structure (KIT-6) were synthesized and modified with aminopropyltriethoxysilane (APTES) for using as adsorbents in carbon-dioxide (CO2)-adsorption application. The CO2-adsorption experiment was carried out at room temperature and atmospheric pressure using 15% CO2 with a flow rate of 20 mL/min and the desorption experiment was carried out at 100°C under N2 balance with a flow rate of 20 mL/min. The adsorption capacity and adsorption rate of all modified mesoporous silicas were enhanced due to the presence of primary amine in the structure, which was able to form a fast chemical reaction with CO2. All adsorbents showed good adsorption performance stability after using over five adsorption/desorption cycles. Due to the effect of the adsorbents’ porous structure on the adsorption/desorption process, an adsorbent with sufficient pore-size diameter and pore volume together with interconnected pore, KIT-6, represents a promising adsorbent that gave the optimum adsorption/desorption performance among others. It showed reasonable adsorption capacity with a high rate of adsorption. In addition, it could also be regenerated with 99.72% efficiency using 12.07 kJ/mmolCO2 of heat duty for regeneration.

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 941
Author(s):  
Jun Liu ◽  
Qiang Chen ◽  
Peng Qi

Upgrading raw biogas to methane (CH4) is a vital prerequisite for the utilization of biogas as a vehicle fuel or the similar field as well. In this work, biogas yield from the anaerobic fermentation of food waste containing methane (CH4, 60.4%), carbon dioxide (CO2, 29.1%), hydrogen sulfide (H2S, 1.5%), nitrogen (N2, 7.35%) and oxygen (O2, 1.6%) was upgraded by dynamic adsorption. The hydrogen sulfide was removed from the biogas in advance by iron oxide (Fe2O3) because of its corrosion of the equipment. Commercial 13X zeolite and carbon molecular sieve (CMS) were used to remove the other impurity gases from wet or dry biogas. It was found that neither 13X zeolite nor CMS could effectively remove each of the impurities in the wet biogas for the effect of water vapor. However, 13X zeolite could effectively remove CO2 after the biogas was dried with silica and showed a CO2 adsorption capacity of 78 mg/g at the condition of 0.2 MPa and 25 °C. Additionally, 13X zeolite almost did not adsorb nitrogen (N2), so the CH4 was merely boosted to ac. 91% after the desulfurated dry biogas passed through 13X zeolite, nitrogen remaining in the biogas. CMS would exhibit superior N2 adsorption capacity and low CO2 adsorption capacity if some N2 was present in biogas, so CMS was able to remove all the nitrogen and fractional carbon dioxide from the desulfurated dry biogas in a period of time. Finally, when the desulfurated dry biogas passed through CMS and 13X zeolite in turn, the N2 and CO2 were sequentially removed, and then followed the high purity CH4 (≥96%).


2014 ◽  
Vol 70 (2) ◽  
pp. 192-199 ◽  
Author(s):  
Yanyan Wang ◽  
Xiang Zhang ◽  
Qiuru Wang ◽  
Bing Zhang ◽  
Jindun Liu

We used natural resources of halloysite nanotubes and alginate to prepare a novel porous adsorption material of organic–inorganic hybrid beads. The adsorption behaviour of Cu(II) onto the hybrid beads was examined by a continuous fixed bed column adsorption experiment. Meanwhile, the factors affecting the adsorption capacity such as bed height, influent concentration and flow rate were investigated. The adsorption capacity (Q0) reached 74.13 mg/g when the initial inlet concentration was 100 mg/L with a bed height of 12 cm and flow rate of 3 ml/min. The Thomas model and bed-depth service time fitted well with the experimental data. In the regeneration experiment, the hybrid beads retained high adsorption capacity after three adsorption–desorption cycles. Over the whole study, the new hybrid beads showed excellent adsorption and regeneration properties as well as favourable stability.


2019 ◽  
Vol 90 ◽  
pp. 01010 ◽  
Author(s):  
Noor Ashikin Mohamad ◽  
Ebrahim Abouzari Lotf ◽  
M. Nasef Mohamed ◽  
Ahmad Arshad ◽  
TAT Abdullah

The paper presents a study for investigating i) the effect of amination of poly(GMA)-grafted polyethylene/polypropylene (PE/PP) substrates with trimethylamine (TMA) and ethylenediamine (EDA) and ii) their impact on carbon dioxide (CO2) adsorption capacity of the obtained adsorbents. The chemical, structural, and morphological changes of the aminated adsorbents were evaluated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. The amination yield with TMA was 40% higher than EDA. However, the obtained adsorbent showed two times lower CO2 adsorption capacity (at 30 bars) than the adsorbent with EDA and stood at 0.6 mmol g-1 compared to 1.2 mmol g-1.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1776
Author(s):  
Phuwadej Pornaroontham ◽  
Gasidit Panomsuwan ◽  
Sangwoo Chae ◽  
Nagahiro Saito ◽  
Nutthavich Thouchprasitchai ◽  
...  

The synthesis of carbon nanoparticles (Cn) and oxygen-doped nanocarbon (OCn) was successfully done through a one-step synthesis by the solution plasma process (SPP). The Cn and OCn were nitrogen-doped by nitridation under an ammonia atmosphere at 800 °C for 2 h to yield NCn and NOCn, respectively, for carbon dioxide (CO2) adsorption. The NOCn exhibited the highest specific surface area (~570 m2 g−1) and highest CO2 adsorption capacity (1.63 mmol g−1 at 25 °C) among the synthesized samples. The primary nitrogen species on the surface of NOCn were pyridinic-N and pyrrolic-N. The synergistic effect of microporosity and nitrogen functionality on the NOCn surface played an essential role in CO2 adsorption enhancement. From the thermodynamic viewpoint, the CO2 adsorption on NOCn was physisorption, exothermic, and spontaneous. The NOCn showed a more negative enthalpy of adsorption, indicating its stronger interaction for CO2 on the surface, and hence, the higher adsorption capacity. The CO2 adsorption on NOCn over the whole pressure range at 25–55 °C best fitted the Toth model, suggesting monolayer adsorption on the heterogeneous surface. In addition, NOCn expressed a higher selective CO2 adsorption than Cn and so was a good candidate for multicycle adsorption.


2020 ◽  
pp. 174751982093803
Author(s):  
Madhavi Jonnalagadda ◽  
Rumana Anjum ◽  
Harshitha Burri ◽  
Suresh Mutyala

Porous carbon and La2O3/porous carbon materials are synthesized for the study of CO2 adsorption and separation by the volumetric method. The synthesized adsorbents are characterized by X-ray diffraction, N2 adsorption–desorption isotherms, Raman spectra and scanning electron microscopy with energy-dispersive X-ray analysis. Characterization results confirm the existence of porosity in the synthesized carbon materials and uniform distribution of lanthanum(III) oxide on porous carbon. The CO2 adsorption capacity for porous carbon and La2O3/porous carbon is 21 and 33 cm3 g−1, respectively, at 298 K and 1 bar. High adsorption of CO2 is obtained for La2O3/porous carbon because of the electrostatic interaction between La2O3 and CO2. Moreover, the N2 adsorption capacity is 2.8 cm3 g−1 for porous carbon and 2.2 cm3 g−1 for La2O3/porous carbon at 298 K and 1 bar. The change in N2 adsorption is due to the decrease in surface area. For La2O3/porous carbon, the selectivity of CO2/N2 is 33.5 and the heat of CO2 adsorption is 36.5 kJ mol−1 at low adsorption of CO2. It also shows constant CO2 adsorption capacity in each adsorption cycle.


Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2831
Author(s):  
Martin Ravutsov ◽  
Yavor Mitrev ◽  
Pavletta Shestakova ◽  
Hristina Lazarova ◽  
Svilen Simeonov ◽  
...  

The post-synthesis procedure for cyclic amine (morpholine and 1-methylpiperazine) modified mesoporous MCM-48 and SBA-15 silicas was developed. The procedure for preparation of the modified mesoporous materials does not affect the structural characteristics of the initial mesoporous silicas strongly. The initial and modified materials were characterized by XRD, N2 physisorption, thermal analysis, and solid-state NMR. The CO2 adsorption of the obtained materials was tested under dynamic and equilibrium conditions. The NMR data revealed the formation of different CO2 adsorbed forms. The materials exhibited high CO2 absorption capacity lying above the benchmark value of 2 mmol/g and stretching out to the outstanding 4.4 mmol/g in the case of 1-methylpiperazin modified MCM-48. The materials are reusable, and their CO2 adsorption capacities are slightly lower in three adsorption/desorption cycles.


2016 ◽  
Vol 840 ◽  
pp. 421-426 ◽  
Author(s):  
Azizul Hakim ◽  
Tengku Sharifah Marliza ◽  
Maratun Najiha Abu Tahari ◽  
Muhammad Rahimi Yusop ◽  
Mohamed Wahab Mohamed Hisham ◽  
...  

Iron oxide (α-Fe2O3) as adsorbent was no longer new in CO2 adsorption studies. However, its contributions in the industry still in limited wherein lack of convincing results of quantifying of adsorbed CO2. This work presents an analysis for α-Fe2O3 was prepared by simple mixing method with identified the adsorption capacity that applied in CO2 capture. The synthesized α-Fe2O3 from different concentrations of precursor were analyzed using XRD, N2 adsorption-desorption isotherms with BET and BJH method, TEM, FTIR, CO2 adsorption at 298 K, CO2-TPD and TGA-DTG. It was noted that 2M concentration of precursor (s2M) with highest crystallite peaks shows highest surface area among all samples which indicative of well generated pores. The different concentration of precursor was found generated more porosity rather than particle size according to TEM micrograph. The sphere shape crystallite particle with high surface area (50.5 m2/g) and porosity were desirable properties in CO2 adsorption. Consequently, physically adsorbed CO2 with adsorption at 298 K was highest with adsorption capacity of at 17.0 mgCO2/gadsorbent. Finally, chemically adsorbed CO2 was successfully identified from CO2–TPD analysis with adsorption capacity of 0.19 mgCO2/gadsorbent and 1.31 mgCO2/gadsorbent at maximum desorption temperature of 375 °C and 749 °C respectively.


2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.


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